TRENTON ­— With two of his alleged accomplices already arrested, a city man on Tuesday still entered an East State Street building where the trio allegedly stole copper roofing over the course of several months, police said.

Trenton police arrested him, as well, bringing charges against all three men for burglary and theft, Lt. Stephen Varn said yesterday.

Myron McKinney, a 46-year-old Trenton resident, also was charged with possession of burglar’s tools, as police found him inside the 200 E. State St. building with copper and the means to remove it, Varn said.

The Trenton Warrant Squad made the initial arrests last Wednesday, apprehending Michael Larkin, 49, of Morrisville, Pa., and Gunther Rohrhircsh, 48, of Trenton, after an investigation yielded warrants for the pair, Varn said.

Further information led them to McKinney nearly a week later, Varn said.

Hamilton resident Mark Dunlap saw the copper slowly disappear from the roof over the course of a year, overlooking the former Bank of America building from his office at the Motor Vehicle Division, he told The Times earlier this month.

Dunlap originally noticed copper disappearing overnight, but eventually saw men on the roof during the day, he said, and they began leaving tools and folding chairs on the roof.

“The one day it really took me by surprise,” Dunlap said. “I looked out the window and said, ‘What the (expletive) is that?’ I see a guy crawling around on the roof in the middle of the day.”

The value of scrap metal constantly fluctuates, but copper now has a value of about $3.18 per pound, according to reports.

Sen. Shirley K. Turner (D-Lawrence) sponsored a bill last year that sought to regulate scrap metal businesses, requiring them to maintain records and paperwork on all transactions, regardless of weight, for 18 months, in an attempt to reduce copper theft.

Gov. Chris Christie called the effort “laudable,” but vetoed the bill in September, citing “substantial expenses and administrative burdens.”

Dunlap posted his most recent Twitter update on the copper theft on Tuesday.